CN1882883B

CN1882883B - System and method for characterizing lithography effects on a wafer

Info

Publication number: CN1882883B
Application number: CN2004800115902A
Authority: CN
Inventors: D·兹格; S·钱
Original assignee: Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 2003-04-29
Filing date: 2004-04-27
Publication date: 2011-03-30
Anticipated expiration: 2024-04-27
Also published as: US7537939B2; WO2004097528A2; US20070275329A1; WO2004097528A3; JP2007528114A; CN1882883A; EP1627258A2

Abstract

In the manufacture of semiconductors, it is often necessary to characterize the effect of line width and line width shape on yield. In an example embodiment, there is a method (200) for randomizing exposure conditions across a substrate. The method comprises generating a list of random numbers (210). A random number is mapped (220) to an exposure field, forming a list of random numbers and corresponding exposure fields. The list or random numbers and corresponding exposure fields is sorted (230) by random number. To each exposure field in the list sorted by random number, an exposure dose is assigned (240). The list is sorted is sorted by exposure field (250).

Description

Be used for the system and method for characterizing lithography to the influence of wafer

The present invention relates to semiconductor technology.More specifically, the present invention relates to determine the influence of the process reform in seeking to improve the process of lithography process performance.

The development that electronics industry still depends on semiconductor technology is with the device of realization higher function in zone more closely.For many application, realize that the device of higher function need be integrated into a large amount of electron devices in the single silicon wafer.Along with the increase of the number of electronic devices of every given area of silicon wafer, it is more difficult that manufacturing process becomes.

Produce a variety of semiconductor devices with multiple application by multiple requirement.This silicon-based semiconductor devices generally includes for example p-channel MOS (PMOS), n-channel MOS (NMOS) and the transistorized mos field effect transistor of complementary MOS (CMOS) (MOSFET), bipolar transistor, BiCMOS transistor.Above-mentioned MOSFET device comprises insulating material between conductive grid and eka-silicon (silicon-like) substrate; Therefore, these devices are commonly called IGFET (insulated gate FET).

Each of these semiconductor devices generally includes the Semiconductor substrate that forms a plurality of active devices thereon.The ad hoc structure of given active device can change between type of device.For example, in MOS transistor, active device generally includes the gate electrode of the electric current between source region and drain region and adjusting source region and the drain region.

An important step is to use photoetching and etching technics to form the part of device or device in the process of making above-mentioned device.In photoetching, wafer substrates is coated with the photochromics that is called photoresist.Then, wafer is exposed; The light that impinges upon on the wafer passes mask plate.This mask plate limits the desirable feature that will be printed on the substrate.After the exposure, developing scribbles the wafer substrates of resist.The desirable feature that is limited on the mask is retained on the substrate that scribbles photoresist.The resist of unexposed area is washed off with developer.Wafer with desirable feature of qualification stands etching.Depend on production run, etching can be wherein use liquid chemical remove the wet etching of wafer material or wherein wafer material stand the dry etching of radio frequency (RF) induction plasma.

Common desirable feature has the specific region, and last zone printed and that be etched must accurately be reproduced in time in this specific region.These are called as critical size (CD).When device geometries during near sub-micrometer range, the wafer manufacturing becomes and more depend on the CD that is consistent in the normal process variation range.The active device size that is designed on the photomask and is replicated and on wafer substrates actual present those must be repeatably with controllable.In many cases, technology attempts to keep last CD to equal to shelter CD.Yet the deficiency in the technology or the change of technology (it can be realized in given manufacturing process, if this technology is " being conditioned ") can present inevitably usually and depart from the last CD that shelters CD.

For improving printing quality, need the influence of sign live width and live width shape usually to yield rate.Generally, under a plurality of conditions,, survey these wafers for yield rate thereafter at one or more key stratums place exposure wafer.For example, quantize the influence of grid width by exposure wafer under various dose to produce a plurality of linear dimensions usually to yield rate.Generally, each wafer of exposure under difference exposure or focal length value.Because silicon and processing cost are expensive, therefore wish on wafer, to obtain identical information; That is, use a series of dosage or focal length exposure wafer.

People's such as Ausschnitt U.S. patent 5,757,507 need to be usually directed to the manufacturing process of photoetching technique, relate to monitoring departing from and aliasing error in being used for photoetching technique that the microelectronics manufacturing uses and etching process more specifically, this to have aspect the monitoring pattern characteristics of the size of the 0.5 μ m order of magnitude, be particularly useful.

People's such as Leroux U.S. patent 5,962,173 is usually directed to make the field of integrated circuit, relates to more specifically making these having extremely narrow kind of thread elements and for example keeping degree of accuracy in the process of the circuit of gate line.

People's such as Leroux U.S. patent 5,902,703 is usually directed to make the field of integrated circuit, relates to more specifically making these having narrow relatively kind of thread elements and for example keeping degree of accuracy in the process of the circuit of gate line.The purpose of this invention also is to check the stepper lens workmanship.

People's such as Ziger U.S. patent 5,976,741 is usually directed to determine to make the method for the interior illuminating exposure dosage of integrated circuit fields and other technological parameter.More specifically, this invention relates to the method for processing semiconductor wafer in step-and-repeat system (step and repeat system).

People's such as Ziger U.S. patent 6,301,008 B1 relates to semiconductor devices and manufacturing thereof, more specifically, relate to be used for developing relative narrow linewidth element for example gate line keep the device and the technology of degree of accuracy simultaneously in its manufacture process.

U.S. patented claim US 2002/0182516 A1 of Bowes is usually directed to the weights and measures of semiconductor fabrication process.More specifically, this invention is to be used for simultaneously device feature being carried out that critical size (CD) is measured with respect to semiconductor wafer and mask overlap being carried out grilling groove (needle comb reticle) pattern to locating tab assembly in the process of processing semiconductor wafer.The full text that is incorporated herein this list of references and above-mentioned those lists of references as a reference.

In a case process, by a series of exposure doses (or focal length) are obtained data to the die exposure of the different column or row on the wafer substrates.In this case process, tube core is printed under multiple exposure dose.Every column of die can be exposed under particular exposure dosage.Along with wafer is passed in user's stepping, exposure dose can increase.Yet, exist a plurality of challenges to solve.The first, incoherently obscure across the yield rate loss meeting of wafer and exposed array.The second, more unintelligible challenge generally is that exposure fields comprises a plurality of tube cores (as being positioned at the mask that is used for wafer stepper).Just comprise the exposure fields of very little tube core, the relation between exposure and the classification chart (sortmaps) is skew easily, and this can cause the false supposition about the relation of yield rate and crucial live width.Classification chart is across wafer substrates tube core drafting one by one, and this wafer substrates has the active device that completed wafer with active device has been carried out electrical measurement (for example " wafer classification ").Classification chart is the electrical test results of the tube core tested on wafer, these tube cores can comprise electrical test patterns and circuit or can be the device with terminal user's purposes, for example memory device, microprocessor, microcontroller, amplifier, special IC (ASIC) etc.In addition, above-mentioned device can be digital device or the analog device made from multiple wafer fabrication process, for example CMOS, BiCMOS, Bipolar etc.Substrate can be that silicon, gallium arsenide (GaAs) or other are applicable to the substrate of making microelectronic circuit thereon.

Along with the past of time, the given wafer substrates with particular example product will demonstrate the classification chart characteristic of the processed wafer substrate that receives in its manufacture process.Along with the increase of the core number of each wafer, the relation between classification chart and the stepper maps becomes and more is difficult to resolve.In addition, stepper maps can be intentionally along any one direction or the both direction skew of level and vertical direction, and this is the relation of complicated two figure further.Thereby, need a kind of method solve following two challenges that the wafer scale exposure characterizes, promptly obscure yield rate and system defect and exposure fields and yield map are aimed at.

In example embodiment, there is a kind of method that is used to make wafer with substrate.This method is included as the exposure fields Random assignment numeral to substrate.Use this Random assignment numeral that exposure parameter is distributed to each exposure fields.According to the exposure parameter processed wafer that distributes.

In another example embodiment, there is a kind of method that is used for across the substrate randomize exposure conditions, this method comprises generation one list of random numbers.Random number is shone upon to exposure fields.The tabulation of random number and corresponding exposure fields forms and is classified according to random number.With exposure dose distribute to according to each exposure fields in the tabulation of random number classification and according to exposure fields to list category.This embodiment is characterised in that exposure fields can be printed under the exposure dose that distributes.

In another example embodiment, there is a kind of method that is used for characterizing lithography to the influence of wafer.This method comprises a plurality of exposure fields of determining the influence that will study and determining to print.Select at least one reference die location.Carry out randomize routine.Reference die is printed so that this reference die apparition under exposure.Each exposure fields is printed under the exposure dose that distributes.Wafer is carried out electrical measurement and electrical measurement and live width are connected.

In another example embodiment, a kind of characterized systematically photoetching technique is to the influence of wafer.This system comprises the device that is used to produce a list of random numbers, be used for random number is shone upon to exposure fields, formed the device of the tabulation of random number and corresponding exposure fields.Exist and to be used for according to random number to the device of the list category of random number and exposure fields and be used for according to the device of exposure fields to list category.After the row classification, there is the device that is used under the dosage that distributes, printing exposure fields.The feature of this embodiment further comprises and is used to select the device of at least one reference die location and is used for printing reference die so that the device of this reference die apparition under exposure.

Above-mentioned general introduction of the present invention is not intended to represent each disclosed embodiment of the present invention or each aspect.In neutralizing detailed description, following figure will provide further feature and example embodiment.

The detailed description of considering following a plurality of embodiment of the present invention can more completely be understood the present invention in conjunction with the accompanying drawings, wherein:

Fig. 1 has summarized and has related to the step of printing exposure dose according to an embodiment of the invention;

Fig. 2 A has illustrated that the example live width figure of the substrate that exposes according to an embodiment of the invention is to characterize the influence of polysilicon grid width to yield rate.

Fig. 2 B has described the electrical measurement of polysilicon CD and the relation between online (inline) scanning electron microscope (SEM) the CD measurement in embodiment according to the present invention technology;

Fig. 2 C is a case process, has described the threshold voltage (V as the function of polysilicon live width _t) decay (roll off) curve;

Fig. 2 D is a case process, and the relative yield rate as the function of live width for five kinds of different polysilicon photoetching processes is shown; And

Fig. 3 has summarized and has related to the step that obtains data in as the described case process of Fig. 2 A-2D according to an embodiment of the invention.

Have been found that the present invention is useful solving aspect two challenges that the user carrying out can running in the process that the wafer scale exposure characterizes, yield rate and system defect are promptly obscured in these two challenges, wherein the user can not differentiate and the changing and with the aligning of exposure fields and yield map, wherein the user can connect particular exposure territory and yield rate by the yield rate of wafer of related particular system.Yield rate should be that the product of electrical testing or the number of test dies are passed through in success.Usually yield rate can be expressed as the number percent of tube core to the test dies number.

Reduce to minimum for the possibility across the defective of wafer that will obscure yield rate and system, method is across the wafer randomize exposure conditions according to an embodiment of the invention.With reference to figure 1.A case method is to produce a list of random numbers 210.Random number is distributed to each exposure fields 220.According to the list category 230 of random number to exposure fields/random number.Exposure dose is distributed to this tabulation 240 according to the random number classification.According to exposure fields this tabulation is classified 250 once more.Each exposure fields is under the dosage that distributes printed 260.

In another example embodiment according to the present invention, the group of 21 ledex exposures (shot) has the random number of distributing to each exposure.Random number can produce with a plurality of well-known methods.They can be by using the table of random numbers manually to produce or producing in the data handling system that comprises computing machine or computing equipment.Can utilize the list of random numbers that software program produces to be needed.This program can be present on the stand-alone computer or pass through the network of customer machine.With reference to the table 1 that is used for the situation of 21 exposure fields.According to random number his-and-hers watches 1 list category.

Reference table 2.Reference table 2.Desirable is to have seven kinds of other exposure doses of level that three times of identical conditions of exposure (for example same dose, focus etc.) are duplicated.These seven kinds of exposure doses are distributed to 21 exposures in 3 groups.

Then, according to the list category of ledex exposure his-and-hers watches 2 to provide according to the randomized exposure of dose distribution.Reference table 3.Certainly, if these domain system ground are different, they can be removed from randomization list so.For example, some territories just are positioned partially on the wafer and because focus effects therefore can be different with interior fields and systematically produce.

Table 1

Distribute to the random number of ledex exposure number

# at random	The exposure number
		10.94668156	1
39.92199435	2
		28.49234129	3
39.97451674	4
		47.11274191	5
80.0428629	6
		95.03925704	7
6.037389413	8
		15.3710325	9
14.3341212	10
		82.40351336	11
1.676129805	12
		36.07767456	13
44.41655076	14
		96.53699358	15
10.86162017	16
		59.76862135	17

8.762993949	18
		22.08926137	19
82.49627786	20
		17.07756739	21

Table 2

According to the classification of random number and attached dosage

# at random	The exposure number	Dosage
			1.676129805	12	Dosage 1
6.037389413	8	Dosage 1
			8.762993949	18	Dosage 1
10.86162017	16	Dosage 2
			10.94668156	1	Dosage 2
14.3341212	10	Dosage 2
			15.3710325	9	Dosage 3
17.07756739	21	Dosage 3
			22.08926137	19	Dosage 3
28.49234129	3	Dosage 4
			36.07767456	13	Dosage 4
39.92199435	2	Dosage 4
			39.97451674	4	Dosage 5
44.41655076	14	Dosage 5
			47.11274191	5	Dosage 5
59.76862135	17	Dosage 6

80.0428629	6	Dosage 6
			82.40351336	11	Dosage 6
82.49627786	20	Dosage 7
			95.03925704	7	Dosage 7
96.53699358	15	Dosage 7

Table 3

According to the exposure number the randomization result

# at random	The exposure number	Dosage
			10.94668156	1	Dosage 2
39.92199435	2	Dosage 4
			28.49234129	3	Dosage 4
39.97451674	4	Dosage 5
			47.11274191	5	Dosage 5
80.0428629	6	Dosage 6
			95.03925704	7	Dosage 7
6.037389413	8	Dosage 1
			15.3710325	9	Dosage 3
14.3341212	10	Dosage 2
			82.40351336	11	Dosage 6
1.676129805	12	Dosage 1
			36.07767456	13	Dosage 4
44.41655076	14	Dosage 5

96.53699358	15	Dosage 7
			10.86162017	16	Dosage 2
59.76862135	17	Dosage 6
			8.762993949	18	Dosage 1
22.08926137	19	Dosage 3
			82.49627786	20	Dosage 7
17.07756739	21	Dosage 3

In according to another embodiment of the present invention, the challenge that the classification of stepper maps and wafer or parameter testing (p test) figure are aimed at can by have a mind to provide one and other off-centered ledex territory very inequality solve, adopt this mode wafer classification chart or the p test pattern can clearly definite thus correlativity.Parameter testing can be included in the device manufacturing processes test at the typical element of the device in a plurality of stages.These tests can comprise transistor, resistor, diode, contact and transit link (contact and via chains) etc., but are not limited thereto.Ball bearing made using, for example available transistor such as ring oscillator, memory module and other typical element are made.

For example, at crucial polysilicon layer place potentially, thereby a territory can be by the serious over-exposed leakage current that causes that all tube cores in this territory show abnormality.Another possibility should be the territory that a territory will cause serious problems of not exposing.For example, at the metallization step place, all tube cores in the described territory are because short circuit should be non-functional.After classification, the chip that lost efficacy showing abnormality is distributed to the ledex territory based on stepper maps.As long as reference marker tube core off-center so just can be determined other correction of gun parallax.With reference to figure 2A.Wafer map 300 illustrates and is intended to characterize the example across the live width of wafer sort of live width to the influence of yield rate.Notice that reference die 310 than the little about 0.10 μ m of next minimum feature, is of a size of about 0.279 μ m.

In case process according to an embodiment of the invention, desirable is that parameter and the yield rate that depends in 5 kinds of different resists coating programs that are used for two multilayer (poly layer) nonvolatile memory process of 0.35 μ m at polysilicon gate layer place characterizes live width.For in 25 200mm wafers a collection of, finishing foregoing, with five wafers of each resist technology coating, thereafter with the identical randomized patterns of 7 kinds of exposure doses each wafer that exposes.Exposure fields is by deliberately over-exposed so that with marking so that online testing and parameter and yield data are connected.Attention is under the situation of this technology not, and it is important that single little tube core and stepper field placement are connected clearly.Reference die 310 demonstrates very strong leakage current, this can allow clearly with classification chart with connect across the live width of this wafer.Measure the live width at all sites place on all wafers at the polysilicon layer place.

Fig. 2 B illustrates the relation between electrical measurement and the online SEM measurement.Figure 32 0 describes the many CD of SEM to measure the curve 325 of this SEM being measured the skew of how electricity performance.Zero offset means that the many CD of physics measure and electric many CD measure the complete shut-down connection.

Another parameter relevant with polysilicon CD is the threshold voltage decay.With reference to figure 2C.Figure 33 0 has described the relation curve 335 of polysilicon CD and threshold voltage decay.

Because each exposure fields comprises a plurality of chips (being 20 in this case), therefore using the yield analysis of this technology is a challenge.Serious over-exposed territory causes the leakage loss of all tube cores of expectation in this territory.This permission inline line width and yield map are interrelated fully.Therefore, each chip in the wafer can then be measured clearly relevant with exposure fields and online many CD.Yield rate can be calculated the ratiometer of exposure chip by good chip under every kind of dosage as the function of average live width.Fig. 2 D illustrates and is used for the relative yield rate as the function of live width that 5 kinds of different overbrushings apply technology.Figure 34 0 has described the relation curve 345 of finished product number percent and many CD.Five kinds of example resist technologies 350 are drawn.Each data point of noting every curve 345 is the average of 700～1000 tube cores.Should emphasize be the data shown in Fig. 2 B-2D be obtain by 25 wafers only and live width the performance parameters of the resist technology of 5 kinds of uniquenesses and the dependence of yield rate are characterized in this is a collection of fully.

In other technology of the feature according to the present invention, can use and use randomize exposure conditions to characterize the influence of a plurality of other alignings of level.For example, can in uniting experiment, study polysilicon and metallization.These signs can illustrate be used to carry out and analyze across the lithography experiments of single wafer based on statistical framework.

With reference to figure 3.In embodiment according to the present invention embodiment, the user can carry out technology 400 subsequently with the manufacturing feature wafer, shown in the example of Fig. 2 A.The user can run in given wafer fabrication process in the modern sub-micron technology of complexity according to his or her experience to be increased in the wafer loss of particular step and the cost of following.As previously mentioned, in the polysilicon layer of example CMOS technology, technology can stand challenge in the zone of printed features.What the user determined to study influences 410.The number of the die sites that will print must be determined 420.Usually, the number at the position that will print is limited by the production tube core that is in the line.For live width and electrical testing being connected, select one or more reference die location 430.Carry out randomize routine 440.For example, the user can carry out the randomize routine 205 that Fig. 1 summarized subsequently.Execute randomize routine 440, the user can be chosen in exposure and print (a plurality of) reference die so that their apparition 450 (being detectable by electrical testing promptly) down.After printing (a plurality of) reference die, each exposure fields is under the dosage that distributes printed 460.For example, sew as the polysilicon of being discussed about Fig. 2 A relevant strongly with leakage current.Usually print one or more reference die in off-centered position.These reference die can be printed in four quadrants of wafer.Specific yield rate restricted problem (yield limiting issue) and technology are understood suitable number and the position of guides user about reference die usually.

The method that this use single wafer solves the challenge that once characterizes a wafer is that it is insensitive to the influence by wafer.For example, if irrelevant defect problem has influenced the single wafer that exposes under given dose, yield rate loss meeting is by mistakenly owing to the live width that is printed on this particular wafer so.Equally, by randomization, reduced across the influence of the systematic effects of wafer to yield rate.At last, this method is lacked than the wafer of the method use that once characterizes a wafer of standard.

The present invention can be merged in the supplementary features as wafer stepping equipment.A plurality of manufacturers, CANON for example, ASML and NIKON make this equipment.The normally computer-controlled and user of this equipment can work out and be used to the complicated process of producing, testing and characterizing.

In embodiment according to the present invention embodiment, wafer stepper can have program to characterize wafer substrates during given technology.For example, thus can in computing machine, work out specific program control step device.Characterization program can be present in program storage, in light, the magnetic storage, maybe can be present in the client/server configuration as the part of internal intranet or internet.As the part of online supervisory system, can be designed for the sample substrate among 25 the group of test.The user enters in the computing machine to control him or she and wants the wafer stepper influence studied.Computing machine produces the tabulation of the die sites that is used for given mask and wafer combination that will print.Computing machine is selected reference die location.Computing machine is carried out randomize routine.After finishing the randomization of selecting die site and selecting reference die location, the computer command wafer stepper is printed tube core under the exposure parameter that distributes.

Though described the present invention with reference to several particular instance embodiment, those skilled in the art will be appreciated that the multiple variation of listing in the claim that can carry out below in the present invention under the situation that does not break away from the spirit and scope of the present invention.

Claims

1. a method (200) that is used to make the wafer with substrate comprising: be the exposure fields Random assignment numeral (210,220) of substrate; Use Random assignment numeral (230,240) is one of other exposure parameters of a plurality of level of each distribution in each exposure fields (250); According to the exposure parameter processed wafer (260) that distributes; Select at least one reference die location; With under exposure, print reference die so that this reference die apparition.

2. method as claimed in claim 1, wherein the exposure parameter of Fen Peiing comprises following at least a: optical near-correction (OPC), characteristic dimension, exposure dose.

3. a method (200) that is used for across the substrate randomize exposure conditions comprising: produce a list of random numbers (210); Random number is shone upon to exposure fields (220), form the tabulation of random number and corresponding exposure fields; According to the list category (230) of random number to this random number and exposure fields; One of a plurality of other exposure doses of level are distributed to according to each exposure fields (240) in the tabulation of random number classification; According to exposure fields to list category (250); Select at least one reference die location; With under exposure, print reference die so that this reference die apparition.

4. method as claimed in claim 3 further comprises: print exposure fields (260) under the exposure dose that distributes.

5. method (410) that is used for characterizing lithography to the influence of wafer, this method comprises: determine the influence (410) that will study; The definite a plurality of exposure fields (420) that will print; Select at least one reference die location (430); Be described a plurality of exposure fields Random assignment numerals (210,220); Use Random assignment numeral (230,240) is one of other exposure parameters of a plurality of level of each distribution in described a plurality of exposure fields (250); Under exposure, print reference die so that this reference die apparition (450); And under the exposure dose that distributes, print each exposure fields (460).

6. method as claimed in claim 5 further comprises, wafer is carried out electrical measurement; And electrical measurement and live width connected.

7. method as claimed in claim 5, wherein reference die location is off-centered.

8. method as claimed in claim 5, wherein the reference die location of Xuan Zeing is positioned at four quadrants on the wafer.

9. method as claimed in claim 5 is wherein carried out randomize routine and is comprised, produces a list of random numbers; Random number is shone upon to exposure fields, form the tabulation of random number and corresponding exposure fields; According to the list category of random number to this random number and exposure fields; Exposure dose is distributed to according to each exposure fields in the tabulation of random number classification; And according to exposure fields to list category.

10. a system that is used to make the wafer with substrate comprises: the device that is used to the exposure fields Random assignment numeral of substrate; Be used for using the Random assignment numeral to come to distribute the device of one of a plurality of other exposure parameters of level for each exposure fields each; Be used for device according to the exposure parameter processed wafer that distributes; Be used to select the device of at least one reference die location; Under exposure, print reference die so that the device of this reference die apparition with being used for.

11. a system that is used for characterizing lithography to the influence of wafer comprises: the device that is used to produce a list of random numbers; Be used for random number is shone upon to exposure fields, form the device of the tabulation of random number and corresponding exposure fields; Be used for according to the device of random number the list category of this random number and exposure fields; Be used for one of a plurality of other exposure doses of level are distributed to the device of each exposure fields in the row of classifying according to random number; Be used for according to the device of exposure fields list category; Be used under the dosage that distributes, printing the device of exposure fields; Be used to select the device of at least one reference die location; Under exposure, print reference die so that the device of this reference die apparition with being used for.

12. a method of making electron device comprises with the step of predetermined close exposure photosensitive layer, wherein adopts according to the method for claim 1 and determines predetermined close.

13. a method of making electron device comprises photoresist is coated in (200) on the substrate; With the predetermined close photoresist that exposes, described dosage adopts a kind of method to pre-determine, and this method is included as the exposure fields Random assignment numeral (210,220) of substrate; Use Random assignment numeral (230,240) is one of other exposure parameters of a plurality of level of each distribution in each exposure fields (250); According to the photoresist (260) on the exposure parameter exposure substrate that distributes; Select at least one reference die location; With under exposure, print reference die so that this reference die apparition.

14. as the method for claim 13, wherein the exposure parameter of Fen Peiing comprises following at least a: optical near-correction (OPC), characteristic dimension, exposure dose.

15. a method of making electron device comprises: photoresist is coated in forms photosensitive layer on the wafer; With the predetermined close photoresist that exposes, described dosage adopts a kind of method to pre-determine, and this method comprises the influence (410) of characterizing lithography to the photosensitive layer of wafer, and this sign comprises: determine the influence (410) that will study; The definite a plurality of exposure fields (420) that will print; Select at least one reference die location (430); Be described a plurality of exposure fields Random assignment numerals (210,220); Use Random assignment numeral (230,240) is one of other exposure parameters of a plurality of level of each distribution in described a plurality of exposure fields (250); Reference die on printing photosensitive layer under the exposure is so that this reference die apparition (450); And in each exposure fields (460) of printing under the exposure dose that distributes on the photosensitive layer.